1. Field of the Invention
This invention relates to a new method of preparing crystalline molecular sieve compositions requiring a reaction mixture for crystallization thereof which contains an adamantane compound as a templating agent.
2. Description of the Prior Art
Zeolitic materials, both natural and synthetic, are known to have catalytic capabilities for many hydrocarbon processes. Zeolitic materials typically are ordered porous crystalline aluminosilicates having a definite structure with cavities interconnected by channels. The cavities and channels throughout the crystalline material generally are uniform in size allowing selective separation of hydrocarbons. Consequently, these materials in many instances are known in the art as "molecular sieves" and are used, in addition to selective adsorptive processes, for certain catalytic properties. The catalytic properties of these materials are affected to some extent by the size of the molecules which selectively penetrate the crystal structure, presumably to contact active catalytic sites within the ordered structure of these materials.
The term "molecular sieve" refers to a material prepared according to the present invention having a fixed, open-network structure, usually crystalline, that may be used to separate hydrocarbons or other mixtures by selective occlusion of one or more of the constituents.
The term "zeolite" refers to a molecular sieve containing a silicate lattice, usually in association with some alumina. In the following discussion, the terms molecular sieve and zeolite will be used more or less interchangeably, since most of the work was carried out on zeolites. However, one skilled in the art will recognize that the teachings relating to zeolites are also applicable to the more general class of materials called molecular sieves.
In recent years, many crystalline zeolites having desirable absorption and catalytic properties have been prepared. Typically, zeolites are prepared from reaction mixtures having sources of alkali or alkaline earth metal oxides, silica, and alumina. More recently, "nitrogenous zeolites" have been prepared from reaction mixtures containing an organic species, usually a nitrogen compound. Depending upon the reaction conditions and the composition of the reaction mixture, different zeolites can be formed even if the same organic species are used. For example, zeolites ZK-4, ZSM-4, faujasite and PHI, have all been prepared from tetramethylammonium solutions.
Although most experiments reported as producing nitrogenous zeolite have used fairly simple organic species such as tetra(n-alkyl)ammonium cations or alkylenediamines, several experiments are reported as using other organic species. U.S. Pat. No. 3,692,470, Ciric, Sept. 19, 1972, discloses preparing ZSM-10 from 1,4-dimethyl-1,4-diazoniabicyclo[2.2.2]octane. U.S. Pat. No. 3,783,124, Rubin et al., Jan. 1, 1974 discloses preparing a zeolite from benzyl trimethylammonium compounds. U.S. Pat. No. 3,832,449, Rosinski et al., Aug. 27, 1974, discloses preparing ZSM-12 from the reaction products of alkylene dihalides with complex amines or nitrogen heterocycles. U.S. Pat. No. 3,950,496, Ciric, Apr. 13, 1976, discloses preparing ZSM-18 from "tris" ammonium hydroxide (1,3,4,6,7,9-hexahydro-2,2,5,5,8,8-hexamethyl-2H-benzo[1,2-C:3,4-C':5,6-C" ]tripyrolium trihydroxide). U.S. Pat. No. 4,000,248, Martin, Dec. 28, 1976, discloses preparing ferrierite using N-methylpyridine. U.S. Pat. No. 4,018,870, Whittam, Apr. 19, 1977, discloses preparing AG5 and AG6 using nitrogenous basic dyes. U.S. Pat. No. 4,251,499, Nanne, Feb. 17, 1981 discloses preparing ferrierite using piperidine or alkyl substituted piperidine. And, U.S. Pat. No. 4,285,922, Audeh, Aug. 25, 1981, discloses preparing ZSM-5 using 1-alkyl-4-aza-1-azaonia-bicyclo[2.2.2]octane-4-oxide halides.
While 1-amino adamantane has been used to crystallize an all-silica clathrasil (a non-porous crystalline silica), it has not been previously known to use these adamantane derivatives to prepare porous molecular sieves including zeolites.